The present invention relates to antibodies to random peptides capable of targeting or specifically binding to gastrointestinal tract (GIT) transport receptors. In particular, this invention relates to methods of using these antibodies as well as specific antibody preparations directed to particular GIT random peptide targeting agents.
Antibodies can be produced by using an immunogen to generate antibodies which immunospecifically bind such an immunogen. Such antibodies include but are not limited to polyclonal, monoclonal, chimeric, single chain, Fab fragments, and an Fab expression library.
Various procedures known in the art may be useful for the production of polyclonal antibodies to an immunogen. For the production of antibody, various host animals, such as rabbits, mice, rats, fowl etc. can be immunized by injection with the immunogen. Various adjuvants may be used to increase the immunological response, depending on the host species, such as Freund""s (complete and incomplete), mineral gels such as aluminum hydroxide, surface active substances such as lysolecithin, pluronic polyols, polyanions, peptides, oil emulsions, keyhole limpet hemocyanins, dinitrophenol, and potentially useful human adjuvants such as BCG (bacille Calmette-Guerin) and corynebacterium parvum.
As disclosed and claimed in WO 98/51325, which reference is hereby incorporated by reference in its entirety, we have identified random peptides and their fragments, motifs, derivatives, analogs or peptidomimetics thereof which are capable of specific binding to GIT transport receptors such as the D2H, hSI, HPT1 and hPEPT1 receptors (hereinafter referred to as xe2x80x9cGIT targeting agentsxe2x80x9d). These GIT targeting agents are capable of facilitating transport of an active agent through a human or animal gastro-intestinal tissue and have use, for example, in facilitating transport of active agents from the lumenal side of the GIT into the portal, hepatic or systemic blood system and/or in targeting active agents to the GIT. Thus, for example, by binding (covalently or noncovalently) the GIT targeting agent to an orally administered active agent, the active agent can be targeted to specific receptor sites or transport pathways which are known to operate in the human gastrointestinal tract, thus facilitating its absorption into the systemic system. Preferably, the active agent is a drug or a drug-containing nano- or microparticle. Preferably, the tissue through which transport is facilitated is of the duodenum, jejunum, ileum, ascending colon, transverse colon, descending colon, or pelvic colon. The tissue is most preferably epithelial cells lining the lumenal side of the GIT.
The GIT targeting agents are bound to a material comprising an active agent. Such compositions have use in targeting the active agent to the GIT and/or in facilitating transfer through the lumen of the GIT into the systemic circulation. Where the active agent is an imaging agent, such compositions can be administered in vivo to image the GIT (or particular transport receptors thereof). Other active agents include but are not limited to: any drug or antigen or any drug- or antigen-loaded or drug- or antigen-encapsulated nanoparticle, microparticle, liposome, or micellar formulation capable of eliciting a biological response in a human or animal. Examples of drug- or antigen-loaded or drug- or antigen-encapsulated formulations include those in which the active agent is encapsulated or loaded into nano- or microparticles, such as biodegradable nano- or microparticles, and which have GIT targeting agents adsorbed, coated or covalently bound, such as directly linked or linked via a linking moiety, onto the surface of the nano- or microparticle. Additionally, the GIT targeting agent can form the nano- or microparticle itself or the GIT targeting agent can be covalently attached to the polymer or polymers used in the production of the biodegradable nano- or microparticles or drug-loaded or drug-encapsulated nano- or microparticles or the peptide can be directly conjugated to the active agent.
The GIT targeting agent bound to the active agent can be employed in methods of treatment (and prophylaxis) by administration to a subject of an effective amount of targeting agent/active agent. Any disease or disorder of interest amenable to therapy or prophylaxis by providing a drug in vivo systemically or by targeting a drug in vivo to the GIT (by linkage to a GIT targeting agent) can be treated or prevented by this administration. Any route of administration known in the art may be used, including but not limited to oral, nasal, topical, intravenous, intraperitoneal, intradermal, mucosal, intrathecal, intramuscular, etc. Preferably, administration is oral.
However, to fully characterize the compositions as well as to determine the fate of the compositions following administration to a subject, antibodies to the specific GIT targeting agents are needed.
The present invention provides antibodies or antibody fragments specific to a domain of a GIT targeting agent, particularly antibodies to ZElan033 (PAX2 15 mer), ZElan088(HAX42-2 20 mer) and ZElan053 (P31 D-form 16 mer).
Additionally, numerous methods are provided below that employ the GIT targeting agent specific antibodies of this invention, including methods of detecting, quantitating, and locating the GIT targeting agent either in a pharmaceutical composition or after contact of a GIT targeting agent-containing composition with human or animal gastro-intestinal tissue.